电机定子振动模态频率分裂特性分析

Analysis of modal frequency splitting characteristics of motor stator vibration

有效抑制由电机径向电磁力激发的电机定子振动是实现电机减振降噪的一个重要途径,而对电机定子模态频率及模态振型的准确分析是抑制电机定子径向振动的基础。采用圆环的弹性力学解析模型作为电机定子振动的分析模型,对无约束状态下电机定子的模态进行分析,得到了电机定子径向振动模态频率和模态振型的解析解。以齿槽和底脚为典型附加结构,采用摄动法对电机定子模态频率的分裂现象进行分析,总结了频率分裂与否以及分裂阶次的判定准则。通过ANSYS有限元软件验证了理论方法和计算的有效性。结果表明,所建立的二维圆环模型可以准确、高效地应用于电机定子模态特性的分析;附加结构的分布形式对定子频率分裂特性具有重要的影响。

A key way to reduce vibration and noise of motor is to effectively suppress the vibration of the motor stator excited by the radial electromagnetic force in the motor,whereas the accurate calculation of modal frequencies and modal shapes is the basis for suppressing the radial vibration of the motor stator.The elasticity analytical model of the circular ring is used as the vibration analysis model of the motor stator,based on which the modal analysis of the motor stator under the unconstrained state is carried out,and the analytical solutions of the modal frequencies and modal shapes of the stator’s radial vibration are obtained.Taking cog⁃ging and footing as typical additional structures,the perturbation method is introduced to analyze the frequency splitting phenome⁃non in the motor stator,and the criteria for determining whether the frequency is split or not and the order of the splitting are sum⁃marized.The validity of the theoretical methods and calculations in this paper is verified by finite element software ANSYS.The re⁃sults show that the established two-dimensional ring model can be accurately and efficiently applied to the analysis of the modal characteristics of the motor stator,and the distribution form of the additional structure has an important influence on the frequency splitting characteristics of the stator.